The Mars Fleet was one of the three main fleets of the Neosapien Commonwealth.
In "The Brood" it was commanded by Shiva. During the Second Battle of Earth and Third Battle of Earth it inflicted severe damage on Exofleet.
In "Fire Ship" it was assembled to decimate Exofleet, but the monitor rigged to destroy the Resolute II self-destructed ahead of time. Typhonus withdrew rather than risk defeat.
In "The Price of Courage" the remainder of the fleet is sent on a suicide mission. While some ships escape, the majority of the capital ships are destroyed in the Fourth Battle of Venus.
In Titan A.E., the remainder of the fleet is assaulted by the Drej at the start of the Second Drej War.